EFFECTS OF SURFACE IRREGULARITIES UPON THE DYNAMIC RESPONSE OF BRIDGES UNDER SUSPENDED MOVING LOADS

Abstract The effects of surface irregularities upon the dynamic response of bridges under suspended moving loads is analyzed by means of a theoretical study. The paper deals with geometrical imperfections of two types, global and local ones. The former may represent irregularities due to permanent loads, creep process or deflections produced by prestressing forces acting on young concrete. The local ones may represent the initial joint or local defects. The vehicle dynamics model is a simple degree of freedom oscillator and the method of analysis used is a Rayleigh-Ritz one. In some cases the amplification factors are found to be much greater than those given by current international design codes and the dynamic effects can no longer be neglected.